Japan chartered larqe quantity of Vichy French merchant ships according to the U.S. Joint Intelligence Committee. Daily summary dated 5 April 1942

For instance the Tranninh owned by Cie. Côtière de l’Annam, Haiphong, French Indochina. Warshipsresearch.blogspot.com

An item reported that Vichy France and the Japanese on 5 April decided that Japan would seize 100,000 tons of the French shipping in Indochina and elsewhere in the Far East. France proposed that Japan would charter 59,000 tons of large ships and 7,000 tons of smaller ships for the Shanghai-Philippines-Japan connection and another 20,000 tons which would France used for the connection between Indochina and Madagascar. The remaning 14,000 tons would be French controlled and used for the coastwise trade in Indochina. The ships were not be used for transporting troops and/or war stores, to be France-flagged and crewed with French officers and sailors. The J.I.C. commented thats proved the shortage of Japanese shipping.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 116 dated 5 April 1942.